How do i solve: 8-3y=4y-13

A pack of five basic solid T-shirts costs $29.95 in a store. The sales tax where they are sold is 7.75%. What is the unit cost o

Anna71 [15]

Answer:

6.45

Step-by-step explanation:

29.95+7.75%=32.27

32.27/5

6.45

3 0

3 years ago

Read 2 more answers

A collection of 20 coins made up of only nickels, dimes, and quarters has a total value of $3.35. If the dimes were nickels, the

Kay [80]

Answer: The required number of quarters in the collection is 11.

Step-by-step explanation: Given that a collection of 20 coins made up of only nickels, dimes and quarters has a total value of $3.35.

If the dimes were nickels, the nickels were quarters and the quarters were dimes, the collection of coins would have a total value of $2.75.

We are to find the number of quarters in the collection.

Let x, y and z represents the number of nickels, dimes and quarters respectively in the collection.

We will be using the following values of nickels, dimes and quarters in form of dollar :

1 nickel = $ 0.05, 1 dime = $ 0.10 and 1 quarter = $0.25.

Then, according to the given information, we have

$x+y+z=20\\\\\Rightarrow x=20-y-z~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)\\\\0.05x+0.10y+0.25z=3.35\\\\\Rightarrow 5x+10y+25z=335\\\\\Rightarrow x+2y+5z=67~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(ii)\\\\0.05y+0.25x+0.10z=2.75\\\\\Rightarrow 5y+25x+10z=275\\\\\Rightarrow y+2z+5x=55~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(iii)$

Substituting the value of x from equation (i) in equations (ii) and (iii), we have

$(20-y-z)+2y+5z=67\\\\\Rightarrow y+4z=47\\\\\Rightarrow y=47-4z~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(iv)$

and

$y+2z+5(20-y-z)=55\\\\\Rightarrow -4y-3z=-45\\\\\Rightarrow y=\dfrac{45-3z}{4}~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(v)$

Comparing the values of y from equations (iv) and (v), we get

$47-4z=\dfrac{45-3z}{4}\\\\\Rightarrow 188-16z=45-3z\\\\\Rightarrow 16z-3z=188-45\\\\\Rightarrow 13z=143\\\\\Rightarrow z=\dfrac{143}{13}\\\\\Rightarrow z=11.$

Thus, the required number of quarters in the collection is 11.

7 0

3 years ago

Why did Marie Antoinette need to marry the French family?

timama [110]

Their common desire to destroy the ambitions of Prussia and Great Britain and to secure a definitive peace between their respective countries led them to seal their alliance with a marriage

4 0

3 years ago

The mean value of 500 homes in a county is $225,000 and the standard deviation is $25,000. approximately how many of the homes i

dusya [7]

240 homes in the county are between $175,000 and $225,000.

The image attached is associated with this question and m in it refers to the mean value which is $225000 here and d refers to the standard deviation which is $25000 here.

Now since m= $225000

and $175000= $225000-$50000= $225000-(2* $25000)= m-2d

Thus, as per the image area covered between m and m-2d= $225000

and $175000 is (34%+14%)of 500 homes= 68% of 500= 240 homes, is the answer.

A random variable X is said to follow a normal distribution if its parameters are mean and standard deviation. Every other distribution can be reduced to a normal distribution.

Learn to know more about normal distributions on brainly.com/question/4079902

#SPJ4

3 0

2 years ago

I need help in my math homework

Anastaziya [24]

Q19.Sunday equals 351 so that plus a hundred equals 451 plus 50 equals 501 so now we round it to closest number wensday at 506

q20.so Thursday and friday added equal 774

q21.Anna's report is 830 Joe's is 670 it would equal 160 more than Joe's so problem is 830 minus 670 equals 160 that is how much more Anna is than joe

q22.ok so week on equals 486 rounded equals 490 next week she got 254 rounded 250 she wanted to earn 545 so if we take 490 and add 50 equals 540 then add 200 and then it's 740 so we now know are answer is near that so I'm going to add them both now 486 plus 254 equals 740 ironically the exact same amount.

q23.ok so 972 minus 468 equals 504 that is how many inches he is bigger than the other one

if you need anymore help just let me know mate

4 0

3 years ago